Sealed radioactive sources are used all over the world for beneficial purposes in areas including medicine, industry, research and agriculture. These sources are usually managed safely and securely while in use. However, after they become disused, sealed sources remain hazardous and must continue to be managed safely and securely. For sources that cannot be re-purposed or recycled, disposal provides the only permanent, safe, secure and sustainable management solution. A fundamental principle is that safety has to be assessed consistent with a graded approach. This ensures that the level of effort applied in carrying out safety assessment is commensurate with the magnitude of the risks from the facility or activity. In accordance with the relevant IAEA safety standards, this publication describes how the graded approach can be applied to post-closure safety assessment for the disposal of disused sealed radioactive sources in boreholes. It is intended primarily for those involved in developing or regulating borehole disposal facilities for disused sealed radioactive sources.

This publication presents the material properties of all unirradiated Uranium–Molybdenum (U-Mo) fuel constituents that are essential for fuel designers and reactor operators to evaluate the fuel’s performance and safety for research reactors. Many significant advances in the understanding and development of low enriched uranium U–Mo fuels have been made since 2004, stimulated by the need to understand irradiation behavior and early fuel failures during testing. The publication presents a comprehensive overview of mechanical and physical property data from U-Mo fuel research.

This publication draws on data and results collated during an IAEA coordinated research project (CRP) on optimizing soil, water and nutrient use efficiency in integrated cropping-livestock production systems. The main objective of the project was to enhance food security, improve soil fertility, and mitigate greenhouse gases from agriculture using integrated cropping-livestock systems in changing climate conditions. In addition, the CRP participants developed a package of technology for farmers to increase crop production and improve their livelihoods using nuclear and related techniques.

There is high interest in new fuel types with increased accident tolerance. These range from using an oxidation resistant coating on zirconium based cladding to alternate fuel and cladding materials. These new fuels/claddings under development must be licensed before being deployed industrially and therefore research is being undertaken to assess their behaviour in various conditions. This publication arises from an IAEA coordinated research project (CRP) dealing with the acquisition of data through experiments on new fuel types and cladding materials and the development of modelling capacity to predict the behaviour of the components and the integral performance of accident tolerant fuel designs under normal and transient conditions. Demonstrations of improvements under severe accident conditions were documented. Several coated cladding materials were produced, tested, characterized and analysed in round robin tests carried out within the CRP. For improvement and validation of fuel performance codes, several benchmarks were organized to compare and analyse predictions of the extended codes. The findings and conclusions of the CRP are summarized in this publication.

Reporting on the results from an IAEA coordinated research project, this publication provides information on reliability data for research reactors. In addition to component reliability data, the publication provides useful information related to the preparation and application of data relevant to initiating events, human reliability, and common cause failures. It also provides guidance on the use and application of the reliability data for research reactors probabilistic safety assessments as a complementary tool to deterministic methods. This publication should be used in conjunction with the relevant IAEA Safety Standards.

Most research reactors share the common characteristics of a long operating lifetime. With the advancement of digital technology, substantial improvements have occurred in the tools that can be applied in the maintenance and monitoring of structures, systems and components (SSCs), enabling an understanding of equipment performance far beyond that available only a few decades ago. Several of these tools, as well as the supporting technology, have been endorsed by regulatory authorities, providing further value to their application to increase availability and reliability of research reactors. These issues and related advancements were the topic of an IAEA coordinated research project and the results are presented in this publication. It provides methods and guidance for monitoring the health of rotating equipment of research reactors to avoid lengthy and costly shutdowns while promoting safe and reliable operation.

A plant information model (PIM) is a set of interlinked information about plant structures, systems and components, incorporating plant data, relationships and rules used to integrate, represent, and describe nuclear facility processes and data, for each phase of the facility lifecycle. Application of the PIM provides an opportunity to radically improve knowledge, information and data capture, integration, use and transfer between stakeholders if industry-wide standards and best practices are adopted. A knowledge-centric plant information model could be developed and leveraged as a modern and efficient approach to better support, manage and enable seamless sharing, transfer and use of sustainable design knowledge within and across each nuclear power plant life cycle phase. The purpose of this publication is to provide an overview of PIMs, emphasize the importance of their application in support and management of design knowledge throughout the nuclear power plant life cycle and present an overview of a knowledge-centric plant information model that builds on the basic concept of a PIM. The target users of this publication are decision-making organizations in Member States having experience with nuclear power programmes and those embarking on new nuclear power programmes.

The limitation of 235U enrichment is a current concern among IAEA Member States. In response, work has been undertaken to provide a platform to facilitate a comprehensive review of the current status, prospects and challenges associated with the use of fuels having enrichments higher than 5 % 235U in light water reactors. This publication is the outcome of two technical meetings and compiles the results and conclusions in terms of benefits to be obtained from the use of high assay low enriched uranium (HALEU) fuel, with due consideration of safety issues that arise from its use. It details technological options and corresponding issues regarding fuel and core design, safety analysis and assessments relevant to manufacturing, handling, transportation, storage, irradiation, and performance in normal and accident conditions.

This publication is the outcome of an IAEA coordinated research project which addressed the problem of advancing salinity in irrigated soils of arid and semi-arid regions. Seven participating countries presented their studies focusing on alternative strategies and on integrated soil and water management practices. The publication informs readers on ways to improve crop productivity and sustainability through water and salinity management and defines approaches and technologies to assess and monitor soil water content and salinity. The test results of a new landscape soil moisture measuring tool (cosmic ray neutron sensor) for area-wide soil water measurements are also presented.

Contractor personnel provide essential services to nuclear power plants (NPPs). They have required levels of competency and must interface effectively with nuclear power plant personnel when performing their assigned duties. It is in this context that this publication offers a framework for assuring the competence of such contractor personnel. This publication reflects the latest practices relevant to the involvement of contractors at NPPs, and details the means currently used to assure their competence. It seeks to provide an understanding of the definition and use of contractors and how they are engaged through the contracting process. The publication will be a useful resource for managers and team leaders of nuclear facilities who are responsible for the competence of NPP personnel including contractors; training staff who are involved in the contracting process; subject matter experts who are involved in the contract specification, and project managers and other staff who may have responsibility for contractor personnel on site.

This publication explains the concepts of quality assurance and quality control. It provides examples, illustrated by good practices, of their implementation within the processes of the management systems of nuclear facilities and describes how they are managed through interfaces with suppliers and subcontractors. The publication discusses the elements of a management system relevant for the quality assurance and quality control functions, such as the generation and retention of documented information. The information presented will help in ensuring the safe and economic operation of nuclear facilities and provide a neutral technical basis for dialogue between government bodies, regulators, plant operators and suppliers when dealing with management system, quality assurance and quality control issues.

There is renewed interest in Member States in the development and deployment of small modular reactors (SMRs). Specific technical characteristics of this reactor type introduce new deployment possibilities. This publication provides current information on considerations about environmental impact assessments (EIAs) related to SMRs. Under many regulatory regimes, the EIA report is a prerequisite for licensing and an important tool to confirm that the potential site is suitable for the future construction and operation of a reactor. Therefore, this publication which discusses approaches to address specific issues related to the EIA for SMRs will be of use to technology holders and licensing authorities.